Predictive bearers in a wireless communication network

ABSTRACT

A method of establishing bearers for a device in a wireless communication network, including collecting for the device data over a period of time from communication sessions the device participates in, the communication sessions supported by a first and second bearer for the network wherein the first bearer transports packets of the second bearer between nodes of the network; calculating from the collected data a likelihood the first bearer will be established for the device at one or more different time values, and predicting the first bearer will be established for the device at a time value if the likelihood of establishment at that time value exceeds a specified threshold; and initiating establishment of the first bearer to establish the first bearer for the predicted time value.

PRIORITY CLAIM

The present application is a National Phase entry of PCT Application No.PCT/EP2019/057807, filed Mar. 27, 2019, which claims priority from EPPatent Application No. 18164584.7, filed Mar. 28, 2018, each of which ishereby fully incorporated herein by reference.

FIELD

This disclosure relates to techniques for establishing bearers within awireless communication network based on predictive techniques.

BACKGROUND

In wireless communication networks, bearers can be used to identifytraffic flows (e.g. IP packet flows) between nodes of the network thathave a common quality of service (QoS) requirement. That is, a bearer isan IP packet flow with a defined QoS between two nodes of a network. Abearer may be viewed as a virtual connection between two nodes of thenetwork.

An example of a communication network that uses bearers is the Long TermEvolution (LTE) network. FIG. 1 schematically illustrates the bearersfor an LTE network.

An LTE network typically includes a device (e.g. a user equipment (UE))102; a base station 104 (referred to as an eNodeB); a serving gateway(SGW) 106; and a packet data network (PDN) gateway (PGW) 108. The SGW106 and the PGW form part of the evolved packet core (EPC). The EPC coremay contain additional components not shown in FIG. 1 for the purposesof clarity. The LTE network connects the device 102 to an externalpacket data network (PDN) 110.

Evolved Packet System (EPS) bearers 112 are a virtual connection betweenthe UE 102 and the PGW 108. The EPS bearer identifies data (e.g. IPpackets) communicated between these two endpoints (i.e. data sent fromthe UE 102 to the PGW 108 and data sent from the PGW 108 to the UE 102)with specific QoS attributes/requirements. In other words, the EPSbearer uniquely identifies traffic flows (e.g. data packets) that have acommon QoS requirement between the UE 102 and the PGW 108. The EPSbearer is a bearer of the LTE network; that is, it connects twoendpoints, or nodes (the UE 102 and PGW 108) that are within the LTEnetwork. External bearer 114 is a virtual connection between the PGW 108of the LTE network and the external packet data network 110.

The EPS bearer provides the PDN connectivity service to the UE 102. EPSbearers are typically created on a per-PDN basis; that is, a set of EPSbearers will be established for each PDN the UE 102 is connected to.This is illustrated schematically in FIG. 2.

In the example shown in FIG. 2, the UE 102 is connected to two packetdata networks 202 and 204. Network 202 is shown as an IP MultimediaSubsystem (IMS) network for delivering IP multimedia data. Network 204is shown as the internet. It will be appreciated that these exampleshave been chosen for the purposes of illustration only.

A first set of EPS bearers 206 provide a virtual connection between theUE 102 and the first PDN 202; and a second set of EPS bearers 208provide a virtual connection between the UE 102 and the second PDN 204.

In some instances, the UE 102 may communicate multiple different typesof data over the network, each with its own QoS requirements. Forexample, the UE 102 may be running multiple applications at a giventime, each having different QoS requirements. To provide some examples,the UE 102 may be concurrently communicating VoIP data and web-browsingdata. Typically, VoIP data has higher QoS requirements than web-browsingdata in some aspects (e.g. lower acceptable delay times), but lower QoSrequirements in other aspects (e.g. packet loss rate). To support thecommunication of data having different QoS requirements, different EPSbearer types can be set up, each associated with different type of QoS.

EPS bearers can be broadly classified into two types: default bearers(e.g. 2061 and 2081) and dedicated bearers (e.g. 2062,3 and 2082).Default bearers are established when a UE attaches to the network, andremain established for the duration of the UE's PDN connection.Dedicated bearers may be established at any time subsequent to theestablishment of the default bearer. Dedicated bearers may beestablished to support communication sessions with specific QoSrequirements. Dedicated bearers may be of different types, eachassociated with a respective QoS.

Referring back to FIG. 1, it can be seen that EPS bearers cross multiplecommunication interfaces of the network. That is, the EPS bearers crossmultiple nodes of the network. Between a given pair of nodes, the EPSbearer maps onto a lower layer bearer. In particular, the EPS bearermaps to an E-UTRAN Radio Access Bearer (E-RAB) bearer 116 between the UE102 and SGW 106. In other words, the E-RAB bearer 116 has two endpoints,the UE 102 and the SGW 106. The EPS bearer also maps to an S5/S8 bearer118 between the SGW 106 and the PGW 108 (i.e., the endpoints of theS5/S8 bearer are the SGW 106 and the PGW 108).

Thus, the EPS bearer 112 consists of the E-RAB bearer and the S5/S8bearer. The EPS bearer may be referred to as the concatenation of theE-RAB bearer and the S5/S8 bearer.

The E-RAB bearer 116 connects the UE 102 to the SGW 106 (morespecifically, it connects the UE 102 to the eNodeB 104, and the eNodeB104 to the SGW 106). The E-RAB transports the data packets of the EPSbearer between the UE 102 and the SGW 106.

The S5/S8 bearer connects the SGW 106 to the PGW 108, and transports thedata packets of the EPS bearer between the SGW 106 and the PGW 108.

The E-RAB bearer maps to a radio bearer 120 and S1 bearer 122 betweenthe UE 102 and SGW 106. In more detail, the E-RAB bearer maps to theradio bearer 120 between the UE 102 and eNodeB 104, and to the S1 bearerbetween the eNodeB 104 and SGW 106. Thus, the E-RAB bearer consists ofthe radio bearer 120 and S1 bearer 122. It may be referred to as theconcatenation of the radio bearer 120 and the S1 bearer 122. The radiobearer transports the data packets of the E-RAB bearer between the UE102 and the eNodeB 104, and the S1 bearer transports the data packets ofthe E-RAB bearer between the eNodeB 104 and the SGW 106.

There is typically a delay in establishing bearers for a communicationsession. For example, dedicated bearers are not established until aftera default bearer has been established, resulting in a potential delayand non-guaranteed QoS until the dedicated bearer is established. Otherbearers (such as the E-RAB or radio bearers) may be particularlysusceptible to congestion, meaning there can also be a delay in tryingto establish these bearers when initiating a communication session.These delays may be undesirable for a user of the UE, and in some casesmay negatively impact the performance of the UE, particularly in caseswhen the UE is running time-sensitive applications, such as gaming, orremote diagnostics.

SUMMARY

According to one aspect of the present disclosure there is provided amethod of establishing bearers for a device in a wireless communicationnetwork, comprising: collecting for the device data over a period oftime from communication sessions the device participates in, thecommunication sessions supported by a first and second bearer for thenetwork wherein the first bearer transports packets of the second bearerbetween nodes of the network; calculating from the collected data alikelihood the first bearer will be established for the device at one ormore different time values, and predicting the first bearer will beestablished for the device at a time value if the likelihood ofestablishment at that time value exceeds a specified threshold; andinitiating establishment of the first bearer to establish the firstbearer for the predicted time value.

The method may further comprise receiving at a node of the network anattach request from the device that includes an identification flagindicating data from communication sessions the device participates inis to be collected for the device, wherein data for the device iscollected following receipt of the identification flag.

The node may be a mobility management entity (MME).

The data may be collected from communication sessions the deviceparticipates in over the period of time.

The collected data may comprise timing data indicating time values thefirst bearer is established for the device.

The collected data may further comprise location data indicating anetwork cell of the communication network the first bearer isestablished in for the device.

The calculating may comprise calculating: (i) a likelihood the firstbearer will be established for the device at one or more different timevalues and (ii) the network cell the first bearer will be established infor the device.

The initiating may comprise initiating establishment of the firstbearer: (i) to establish the first bearer for the predicted time; and(ii) within the network cell the first bearer is predicted to beestablished in at the predicted time value.

The method may further comprise deactivating the first bearer if it isdetermined the device has not used the first bearer within a specifiedtime period of the establishment of the first bearer.

The method may further comprise starting a timer when the first beareris established, and initiating deactivation of the first bearer if thetimer indicates the device has not used the first bearer within thespecified time period.

The first bearer may be a radio bearer. The first bearer may be anE-UTRAN Radio Access Bearer (E-RAB).

The second bearer may be a default bearer or a dedicated bearer. Thesecond bearer may be an EPS bearer.

According to another aspect of the present disclosure there is providedan apparatus for establishing bearers for a device within a wirelesscommunication network, comprising: a data store configured to collectdata for the device over a period of time from communication sessionsthe device participates in, the communication sessions supported by afirst and second bearer for the network wherein the first bearertransports packets of the second bearer between nodes of the network; acomputation module configured to calculate from the collected data alikelihood the first bearer will be established for the device at one ormore different time values, and predict the first bearer will beestablished for the device at a time value if the likelihood ofestablishment at that time value exceeds a specified threshold; and acommunications module configured to initiate establishment of the firstbearer to establish the first bearer for the predicted time value.

BRIEF DESCRIPTION OF FIGURES

The present disclosure will now be described by way of example withreference to the accompanying drawings. In the drawings:

FIG. 1 shows a schematic illustration of bearers within an LTE network.

FIG. 2 shows a schematic illustration of EPS bearers within an LTEnetwork.

FIG. 3 shows an example of an LTE network in accordance with anembodiment of the present disclosure.

FIG. 4 shows a flowchart of steps for establishing a first bearer usingpredictive techniques.

FIG. 5 shows a call flow illustrating an attach request for a UE'sattachment to a network.

FIG. 6 shows a call flow illustrating the establishment of an E-RAB at apredicted time of use by the UE.

FIG. 7 shows a call flow illustrating the deactivation of theestablished E-RAB after a specified time period of non-use by the UE.

FIG. 8 shows an example LTE network in accordance with anotherembodiment of the present disclosure.

FIG. 9 shows a flowchart of steps for establishing a dedicated bearerusing predictive techniques.

FIG. 10 shows a call flow illustrating the identification of a UE forwhich session information is to be recorded.

FIG. 11 shows a call flow illustrating the establishment of a dedicatedbearer at a predicted time of use by the UE.

FIG. 12 shows a call flow illustrating the deactivation of theestablished dedicated bearer after a specified time period of non-use bythe UE.

DETAILED DESCRIPTION

The present disclosure is directed to approaches for establishingbearers within a wireless communication network using predictivetechniques. The bearers can be established within the network for adevice on the basis of predictions made from data collected fromcommunication sessions the device participates in. The predictionsestimate the likelihood, or probability, for one or more different timesthat the device will use the bearer as part of a communication sessionat that time. If an estimated likelihood that a bearer will beestablished at a particular time exceeds a specified threshold,establishment of that bearer is initiated so that the bearer isestablished at that time. By establishing a bearer based on a predictedlikelihood of use, the bearer can be established and ready for use forthe time it is needed by the device. This may reduce the delayassociated within establishing certain types of bearers within thenetwork.

Two general classes of examples for establishing bearers will bedescribed herein. The first set of examples relate to establishing afirst bearer that transports data packets of a second bearer betweennodes, or components of the network. In these examples, the secondbearer comprises the first bearer; in other words, the second bearer isthe concatenation of the first bearer and some other third bearer. Putanother way, the second bearer is a higher layer bearer than the firstbearer/the first bearer is a lower layer bearer than the second bearer.The first bearer could for example be an E-RAB bearer, or a radiobearer. The second bearer could be an EPS bearer (if the first bearer isan E-RAB bearer), or the second bearer may be an E-RAB bearer (if thefirst bearer is a radio bearer).

The second set of examples relate to establishing a dedicated bearer.

These examples will now be described in more detail with reference toFIGS. 3 to 12. These examples will describe the establishment of bearersin the context of an LTE network. It will be appreciated that this isfor the purposes of illustration only, and that the following techniquesand approaches can be applied within different types of wirelesscommunication networks that implement bearers.

FIG. 3 shows an example of an LTE network 300. The network comprises auser equipment (UE) 302, an eNodeB 304, and an evolved network core(EPC) 306. The EPC connects to an external packet data network 308,which in the example illustrated here is the internet.

The UE may be any suitable type of device capable of participating inwireless communications. The UE could be, for example, a mobile phone,smartphone, laptop, PC, tablet, etc.

The eNodeB 304 is an example of a base station and operates to connectthe UE to the EPC 306. As described above with reference to FIG. 1, aradio bearer 120 provides a virtual connection between the UE 302 andthe eNodeB 304. An S1 bearer provides a virtual connection between theeNodeB 304 and the EPC 306.

The EPC comprises a number of components. In the example shown, theseare: a mobility management entity (MME) 310; a serving gateway (SGW)314; a packet data network gateway (PGW) 318; a policy charging andrules function (PCRF) unit 316 and a home subscriber server (HSS) 312.Each of these components may be referred to herein as nodes. The MME 310is shown in more detail and comprises a communications interface 320; apredictive dedicated bearer data store 322; a computation unit 324, acommunications module 328 and optionally a timer 326.

A brief overview of the components within the EPC 306 will now bedescribed.

The MME 310 operates to process the signalling between the UE 302 andthe EPC 306. The MME 310 also operates to select an SGW for a UE duringan initial attachment, and to select a PGW.

The SGW 314 is responsible for controlling handovers of the UE 302 toneighbouring eNodeBs. The SGW 314 may also retain information on thebearers when a UE is an idle state. It can buffer downlink data whilethe MME 310 operates to re-establish a bearer. The SGW 314 alsofunctions as a router between the eNodeB 304 and the PGW 318.

The PGW 318 operates to provide connectivity between the UE 302 and theexternal PDN 308. It is the point of entry to or exit from the LTEnetwork of data packets for the UE 302.

The HSS 312 contains subscription data for users of the network. It maystore information about the PDN's a UE can connect to. The HSS may alsostore the identity of the MME to which the UE is currently attached, orregistered.

The PCRF 316 performs policy control and decision making. It can provideQoS authorisation for UE's participating in communication sessions andmanage data flows in accordance with a user's subscription profile.

The operation of the network nodes to establish a bearer based on apredicted likelihood of use by the UE 302 will now be described withreference to FIG. 4. FIG. 4 outlines a process to establish a firstbearer that transports data packets of a second bearer between two nodesof the network 300. Both the first bearer and the second bearer have astheir endpoints nodes within the LTE network 300. In accordance with theexamples that will now be described, the first bearer is the E-RABbearer, which transports data packets of the EPS bearer (the ‘secondbearer’) between two nodes of the LTE network (the UE 302 and the SGW314).

At 402, data from communication sessions the device participates in iscollected over a period of time. The data is used to profile thecommunication sessions the device participates in over the period oftime. More specifically, the data may be used to profile requests toestablish an E-RAB bearer to support a communication session the deviceis participating in. In other words, data is collected to profile theestablishment of E-RABs used by the device (i.e. established to supporta communication session the device is participating in) over a period oftime. The device may be said to be participating in a communicationsession when it is connected to a PDN.

The MME 310 performs 402. The MME 310 may only collect data for certainUE's in the network 300. For example, the MME 310 may collect data onlyfor UE's that have subscribed to a particular service provisioned by thenetwork 300. The MME 310 may identify UEs it is to collect session datafor through a flag communicated by the UEs. For clarity, this flag maybe referred to herein as a predictive E-RAB (pERAB) flag. Thus, the MME310 collects session data for UE's tagged by the pERAB flag.

The pERAB may conveniently be provided in a new field of the AttachRequest message communicated from the UE to the MME. This message may bea request for attachment to the network 300, as illustrated in FIG. 5.

As shown in FIG. 5, the UE 302 communicates an Attach Request message502 to the MME to request attachment to the network. The message 502 ismodified to include a field for the pERAB flag. Though FIG. 5 shows theattach request being sent directly from the UE 302 to the MME 310, inpractice the attach request may be routed from the UE 302 to the MME 310via the eNodeB 304. Thus, the UE 302 may communicate the Attach Requestmessage (containing the E-RAB flag) to the eNodeB 304. The AttachRequest message may further include an identification of the UE 302,such as the International Mobile Subscriber Identity (IMSI). The AttachRequest message may include additional information, for example asspecified in the 3GPP Technical Specification (TS) 23.401. The eNodeB304 forwards the Attach Request message to the MME 310. The message maybe forwarded to the MME 310 in a control message, or Initial UE message.The remainder of the attach procedure may proceed in its normal fashion,e.g. as outlined in TS 23.401 section 5.3.2.1).

Referring to FIG. 3, the MME 310 may receive the Attach Request message502 through its communications interface 320. The received message maythen be sent to the data store 322. The data store 322 may identify fromthe received message that the pERAB flag for the UE 302 is set. In otherwords, the data store 322 may determine from the device identificationidentifying the UE 302 (e.g. the IMSI) and the set pERAB flag within theAttach Request Message, that session data is to be collected forcommunication sessions the UE 302 participates in. Thus, the MME 310collects data for subsequent communication sessions the UE 302participates in following the initial attachment to the network.

The information collected by the MME 310 for each of the UE'scommunication sessions could include one or more of: a) identificationinformation for the UE 302 (e.g. the UE's IMSI); b) timing informationindicating the time an E-RAB bearer was established to support thecommunication session the UE 302 was participating in; c) locationinformation indicating: i) the network cell the UE 302 is located inwhen the communication session was established, or ii) the network cellthe UE 302 was located in at the time the E-RAB bearer was established;d) application information identifying the type of application runningon the UE 302 the E-RAB bearer is being used for (e.g. the type ofnetwork data communicated as part of the session being supported by theE-RAB), such as VoIP, video calling, video streaming, gaming etc.

The timing information may be in the form of a timestamp. The timinginformation may identify a time of day at which the E-RAB wasestablished. The timing information may optionally additionally identifya day of the week at which the E-RAB was established, and/or thecalendar date on which the E-RAB was established. Thus, the ‘time’ theE-RAB was established may refer to a time of day, or optionally a timeof day and day of week, or a time and date.

Thus, the MME 310 may collect, for each communication session the UE 302participates in over some period of time: the time the E-RAB bearer wasestablished to support the communication session; a location of thenetwork cell the UE 302 was located in at the time the E-RAB wasestablished; and optionally information characterizing the type ofapplication the established E-RAB bearer was used for.

Referring back to FIG. 4, and at 404 the collected data is used toestimate, for one or more different time values, the likelihood an E-RABwill be established to support a communication session for the UE 302 atthat time value. The likelihood may take the form of a calculatedprobability. That is, for one or more different time values (e.g. a timeof day; a time of day and day of week, etc.) a likelihood, orprobability, that an E-RAB will be established for the UE 302 at thattime value is calculated.

The computation unit 324 of the MME 310 (shown in FIG. 3) may perform404. The computation unit 324 may perform a predictive algorithm tocalculate the probabilities the E-RAB will be established at one or moredifferent times.

The estimated likelihoods may be calculated from the data collected foreach of the communication sessions the UE 302 participates in over thetime period. The computation unit 324 may refine its estimatedlikelihood each time data additional data is collected for the UE 302,i.e. each time additional data is collected by the data store 322 for acommunication session the UE 302 is participating in. In other words,the computation unit 324 may update its estimated likelihood each timedata for a new communication session the device participates in isrecorded in the data store 322.

Because the chances of an E-RAB being established for the UE 302 at thesame time (e.g. to within the same minute) on different days may berelatively low, the computation unit 324 may calculate the likelihoodthat the E-RAB will be established for the UE 302 within a particulartime interval. That time interval could be for example be of the orderof minutes, e.g. a 5 minute interval, a 10 minute interval etc. Thecalculated likelihood for the time interval may then be ascribed to aparticular time within that time interval. That time value mayconveniently be the beginning of the time interval.

The estimated likelihood an E-RAB will be established for the UE 302within a specific time interval may be calculated as a function of: i)the number of times an E-RAB was established for the UE 302 within thespecific time interval for each day the session information wascollected and recorded; and ii) the number of days over which thesession information was collected and recorded. As a simple example, ifthe session information was recorded over a time period of 10 days, andan E-RAB was established for the UE 302 within the time interval between10:00 am and 10:10 am on 7 of those days, the estimated likelihood anE-RAB will be established for the UE 302 within the time intervalbetween 10:00 am and 10:10 am may be calculated as 0.7, or 70%. Theestimated likelihood for the time interval may then be ascribed to thetime value defining the beginning of the time interval (in this example,10:00 am).

It will be appreciated that other, more complex, predictive calculationsmay be used.

In some examples, the network cell location is not taken into account inthe predictive calculations performed by the computation unit 324. Thatis, the estimated likelihood of E-RAB establishment may be calculatedusing only the timing information in the data store 322, and excludingthe location information. This may be useful for estimating when E-RABbearers are likely to be established for UE's that use regularly use thesame services at similar times for each day, but from differentlocations.

In other examples, the estimated likelihood an E-RAB will be establishedmay be calculated by the computation unit 324 additionally in dependenceon the location of the UE 302 within the network. That is, thecalculation unit 324 may use the location information recorded in thedata store 322 to estimate: i) the likelihood an E-RAB will beestablished for the UE 302 at one or more time values; and ii) thenetwork cell that E-RAB will be established in for the UE 302 (i.e., thenetwork cell the device will be located in when that E-RAB isestablished).

The estimated likelihood an E-RAB will be established may additionallybe calculated by the computation unit 324 in dependence on the type ofapplication, or service, running on the UE 302. That is, the computationunit 324 may use the information recorded in the data store 322 toestimate: i) the likelihood an E-RAB will be established for the UE 302at one or more time values; and ii) the type of application, or service,running on the UE 302 that E-RAB will be established for.

In some examples, the computation unit 324 may estimate: i) thelikelihood an E-RAB will be established for the UE 302 at one or moretime values; and ii) the network cell that E-RAB will be established infor the UE 302; and iii) the type of application, or service, running onthe UE 302 that E-RAB will be established for.

If the estimated likelihood an E-RAB bearer will be established for theUE 302 at a particular time value exceeds a specified threshold, thecomputation unit 324 may predict that the E-RAB bearer will beestablished for the UE 302 at that time value (step 406). That timevalue may be referred to herein as a predicted time value. Thecomputation unit 324 may additionally predict which network cell theE-RAB will be established in, and/or the application or service runningon the UE 302 the E-RAB will be established for. That is, thecomputation unit 324 may predict the network cell the E-RAB will beestablished in at the predicted time value.

Decision logic may be used to implement 406. That is, the computationunit may make a prediction that the E-RAB will be established at a timevalue if the associated likelihood exceeds the specified threshold, andnot make a prediction if the likelihood is below the specifiedthreshold.

The specified threshold may be set by the MME 310. The value of thethreshold may depend on the associated time value. For example, a lowerthreshold may be associated with ‘peak’ time values (e.g. time values atwhich the network is expected to be particularly busy). During thesetime values it may be more important from a performance perspective tohave the E-RAB established in time for its use by the UE 302. It maytherefore be desirable to lower the threshold to reduce the risk of abearer not being established for the UE 302 when one was needed. Thevalues of the threshold may alternatively or in addition depend on theassociated type of service the E-RAB will be established for. Forexample, certain types of service (e.g. gaming) are more time-criticalthan others (e.g. web browsing). It may therefore be preferable to havea lower prediction threshold for the more time-critical services toreduce the risk of a bearer for that service not being established forthe UE 302 when one was needed.

Thus, in summary, at 404 the computation unit 324 estimates thelikelihood an E-RAB will be established for the UE 302 at one or moretime values (and optionally, also the network cell the E-RAB will beestablished in and/or the service running on the UE 302 the E-RAB willbe established for). If any of those estimated likelihoods exceed aspecified threshold, then at 406 the computation unit 324 may predictthat an E-RAB will be established at the corresponding time value(s)(and optionally, predict the network cell the E-RAB will be establishedin and/or the service running on the UE 302 the E-RAB will beestablished for).

At 408, the MME 310 initiates the establishment of an E-RAB for the UE302 so that the E-RAB is established by the time value at which thelikelihood exceeds the specified threshold (i.e. by the predicted timevalue). That is, the MME 310 initiates the establishment of the E-RAB atsome time prior to the predicted time value so that the E-RAB isestablished by the predicted time value. The MME 310 may initiate theestablishment some specified time period before the predicted timevalue. This time period may be dependent on the average or typical timetaken to establish an E-RAB.

If at 404 the computation unit additionally predicts the network cellthe E-RAB will be established in for the UE 302, then at 408 the MME 310initiates the establishment of the E-RAB in that network cell. That is,the MME 310 initiates the establishment of the E-RAB so it isestablished at the predicted time value and in the predicted networkcell (i.e. the network cell the first bearer is predicted to beestablished in at the predicted time value). The establishment of theE-RAB is illustrated in FIG. 6.

FIG. 6 shows a call flow for UE requested bearer resource modification.Initially, the UE 302 sends a bearer resource modification request 602to the MME 310. At 3 a (block 604), the MME 310 initiates theestablishment of an E-RAB at a predicted time value TP. To initiate theestablishment of the E-RAB bearer, the MME 310 communicates a bearerresource command message 606 to the SGW 314. This message may be sent bythe communications module 328 via the interface 320.

In response to receiving the command 606, the SGW 314 sends a return‘create bearer request’ message 608 back to the MME 310. This contrastswith the conventional call flow depicted in 3GPP TS 23.401, where theSGW 314 sends the bearer resource command to the PGW 318. In accordancewith the present disclosure, the SGW 314 answers the bearer resourcecommand 606 to establish the E-RAB.

In response to receiving the create bearer request 608 from the SGW 314,the MME 310 communicates an E-RAB setup request message 610 to theeNodeB 304. In response to receiving this message, the eNodeB 304establishes the radio bearer with the UE 302. This is done through theexchange of RRC reconfiguration messages 612 and 614. Once establishmentof the radio bearer is complete, the eNodeB 304 communicates an E-RABsetup response message 616 back to the MME 310. In response, the MME 310communicates a create bearer response message 618 back to the SGW 314 tocomplete the establishment of the E-RAB between the UE 302 and the SGW314.

The call flow may then continue with the exchange of further messagesdenoted generally at 620 (e.g. as per 3GPP TS 25.401).

The MME 310 may be configured to initiate deactivation of the E-RABestablished at step 408 in response to determining that the bearer isnot used by the UE 302 within a specified time period tmax of itsestablishment. This can conveniently free up resources of the network ifit is determined the UE 302 is in an idle mode.

The time period tmax may be of the order of minutes. In some examples,tmax=1, 2, 3, 4, 5 or 10 minutes.

To monitor whether to initiate deactivate the established E-RAB, the MME310 may start timer 326 when the E-RAB is established. If the MME 310detects that the E-RAB has not been used by the UE 302 upon expiry ofthe waiting time tmax, it initiates deactivation of the E-RAB. The timer326 may then be reset.

FIG. 7 is a call flow illustrating the deactivation of the E-RABestablished from predictions made at 404 from the session data collectedat 402.

FIG. 7 is based on the call flow illustrating PGW-initiated bearerdeactivation per 3GPP TS 23.401, but with some modifications which willbe explained below.

At 1, the PCRF 316 sends an IP-CAN session modification message 702 tothe PGW 318. In response, the PGW 318 sends a ‘delete bearer request’message 704 to the SGW 314. At 3 a, the MME 310 receives from the SGW314 a delete bearer request message 706.

Which of 4 a-4 c are performed by the MME 310 will depend on the reasonfor deactivating the bearer. When bearer deactivation is neither due toIdle State Signalling Reduction (ISR) deactivation nor handover tonon-3GPP accesses, 4 a is performed. If the UE 302 is in an idle stateand the reason for releasing the bearer is because of a request forreactivation, 4 b is performed.

The 4 bii is a new task performed by the MME 310 in accordance with thepresent disclosure. In accordance with this example, the MME 310determines that the established E-RAB has not been used by the UE 302within the time period tmax of its predicted time. Thus, the UE 302 maybe in an idle state. In response to this determination, the MME 310sends a deactivate bearer request message 708 to the eNodeB 304 toinitiate deactivation of the E-RAB. This message may be sent by thecommunications module 328 via the interface 320.

In response to receiving message 708, the eNodeB 304 releases the radiobearer through messages 710, 712 and 714. The call flow then continuesthrough the exchange of messages denoted generally at 716 in accordancewith 3GPP TS 23.401.

Thus, in summary, the MME 310 communicates a deactivate bearer requestmessage 708 to the eNodeB 304 to initiate deactivation of theestablished E-RAB in response to determining the E-RAB has not been usedby the UE 302 within a maximum time period tmax of its establishment atstep 406.

The above examples describe an approach for predicting a time at whichan E-RAB will be established for a UE 302 (and potentially the networkcell it will be established in), and initiating establishment of theE-RAB at that predicted time (and optionally in the predicted networkcell). It will be appreciated that the above-described techniques couldbe equivalently applied to predict a time at which a radio bearer willbe established for a UE, and initiating establishment of the radiobearer at that predicted time.

To predict the establishment of a radio bearer, the data store 322 mayrecord data from the communication sessions the UE 302 participates into profile over a time period requests to establish a radio bearer forthe UE 302. In other words, data is collected to profile theestablishment of radio bearers used by the UE 302. In this case, thedata collected by the MME 310 for each of the UE's communicationsessions may include timing information indicating the time the radiobearer was established to support that communication session.

The computation unit 324 may then estimate the likelihood a radio bearerwill be established for the UE 302 at one or more different time values,e.g. using any of the techniques described above with reference to step404.

If an estimated likelihood that a radio bearer will be established forthe UE 302 exceeds a specified threshold at a particular time value, theMME 310 can initiate establishment of the radio bearer at that timevalue. The MME 310 may do this by sending a bearer resource commandmessage 606 to the SGW 314 as described above with reference to FIG. 6.

In an analogous fashion to the E-RAB examples described above, the MME310 may also estimate from the collected data the network cell the radiobearer will be established in for the UE 302, and/or the service runningon the UE 302 that radio bearer will be established for. The MME 310 canthen initiate establishment of the radio bearer in that estimatednetwork cell.

A further set of examples will now be described for establishing adedicated EPS bearer using predictive techniques.

FIG. 8 shows a further example of an LTE network 800. The networkcomprises a user equipment (UE) 802, an eNodeB 804, and an evolvednetwork core (EPC) 806. The EPC 806 connects to an external packet datanetwork 808, which in the example illustrated here is the internet. TheEPC 806 comprises: a mobility management entity (MME) 810; a servinggateway (SGW) 814; a packet data network gateway (PGW) 818; a policycharging and rules function (PCRF) unit 816 and a home subscriber server(HSS) 812. Also shown is an application function (AF) 828. The AF is acomponent external to the EPC 806 and operates to provide session andmedia related information to the PCRF 816.

The components of this network, with the exception of the MME 810 andPCRF 816, operate in the same manner as the corresponding componentsshown in FIG. 3 and so a description of these components will not berepeated here.

The MME 810 may be a standard MME node (i.e. it may not include thecomponents of the MME 310). The PCRF 816 is shown in more detail andcomprises a communications interface 820; a predictive dedicated bearerdata store 822; a computation unit 824, a communications module 803 andoptionally a timer 826.

The operation of the network nodes to establish a dedicated bearer basedon a predicted likelihood of use by the UE 802 will now be describedwith reference to FIG. 9. FIG. 9 outlines a process to establish adedicated bearer that transports data packets between two nodes of thenetwork 800. The dedicated bearer has as its endpoints nodes within theLTE network 800. In particular, the dedicated bearer is an EPS bearerthat has as its endpoints the UE 802 and PGW 818.

At 902, data from communication sessions the UE 802 participates in iscollected over a period of time. The data is used to profile thecommunication sessions the device 802 participates in over the period oftime. More specifically, the data may be used to profile requests toestablish a dedicated bearer to support a communication session the UE802 is participating in. In other words, data is collected to profilethe establishment of dedicated bearers used by the device 802 (i.e.established to support a communication session the device isparticipating in) over a period of time.

The PCRF 816 performs 902. The PCRF 816 may only collect data forcertain UE's in the network 800. For example, the PCRF 816 may collectdata only for UE's that have subscribed to a particular serviceprovisioned by the network. The PCRF 816 may identify UE's it is tocollect session data for through a flag communicated to the PCRF 816.For clarity, this flag may be referred to as a predictive dedicatedbearer (PDB) flag. Thus, the PCRF 816 collects session data for UE'stagged by the PDB flag.

The PDB flag may conveniently be provided in a field of a messagereceived at the PCRF 816 from the AF 828 to modify the sessioninformation. This is illustrated in FIG. 10.

FIG. 10 shows at 1002 the UE 802 requesting attachment to the networkand the establishment of a PDN session, including bearer creation.Following creation of the session, user data plane traffic iscommunicated between the UE 802 and the network, shown at 1004.

The AF sends a modify session information message 1006 to the PCRF 816.This message indicates the PCRF 816 is to store updated, or modified,information for the session the UE 802 is participating in. Includedwithin that message is the PDB flag. Also included within the message1006 is an identification of the UE 802, such as the InternationalMobile Subscriber Identity (IMSI).

The PCRF 816 receives the modify session information message 1006through its communication interface 820. The received message may thenbe sent to the data store 822. The data store 822 may identify from thereceived message that the PDB flag for the UE 802 is set. In otherwords, the data store 822 may determine from the device identificationidentifying UE 802 (e.g. the IMSI) and the set PDB flag within themodify session information message from the AF 828 that session data isto be collected for communication sessions device 802 participates in.Thus, the PCRF 816 collects data for communication sessions afterdetecting the PDB flag. This is illustrated in FIG. 10 at block 1008.

The information collected by the PCRF 816 for each of the UE'scommunication sessions could include one or more of: a) identificationinformation for the UE 802 (e.g. the UE's IMSI); b) timing informationindicating the time a dedicated bearer was established to support thecommunication session the UE 802 was participating in; c) locationinformation indicating: i) the network cell the UE is located in whenthe communication session was established, or ii) the network cell theUE was located in at the time the dedicated bearer was established; d)application information identifying the type of application running onthe UE 802 the dedicated bearer is being used for (e.g. the type ofnetwork data communicated as part of the session being supported by thededicated bearer), such as VoIP, video calling, video streaming, gaming,etc.

The timing information may be in the form of a timestamp. The timinginformation may identify a time of day at which the dedicated bearer wasestablished. The timing information may optionally additionally identifya day of the week at which the dedicated bearer was established, and/orthe calendar date on which the dedicated bearer was established. Thus,the ‘time’ the dedicated bearer was established may refer to a time ofday, or optionally a time of day and day of week, or a time and date.

Thus, the PCRF 816 may collect, for each communication session the UE802 participates in over some period of time: the time the dedicatedbearer was established to support the communication session; a locationof the network cell the UE 802 was located in at the time the dedicatedbearer was established; and optionally information characterizing thetype of application the established dedicated bearer was used for.

Referring back to FIG. 9, and at 904 the collected data is used tocalculate, for one or more different time values, the likelihood adedicated bearer will be established to support a communication sessionfor the UE 802 at that time value. The likelihood may take the form of acalculated probability. That is, for one or more different time values(e.g. a time of day; a time of day and day of week, etc.) a likelihood,or probability, that dedicated bearer will be established for the UE 802at that time value is calculated.

The computation unit 824 of the PCRF 816 (shown in FIG. 8) may perform904. The computation unit 824 may perform a predictive algorithm tocalculate the probabilities the dedicated bearer will be established atone or more different times.

The estimated likelihoods may be calculated from the data collected foreach of the communication sessions the UE 802 participates in over thetime period. The computation unit 824 may refine its estimatedlikelihood each time data additional data is collected for the UE 802,i.e. each time additional data is collected by the data store 822 for acommunication session the UE 802 is participating in. In other words,the computation unit 824 may update its estimated likelihood each timedata for a new communication session the device participates in isrecorded in the data store.

Because the chances of a dedicated bearer being established for the UE802 at the same time (e.g. to within the same minute) on different daysmay be relatively low, the computation unit 824 may calculate thelikelihood that the dedicated bearer will be established for the UE 802within a particular time interval. That time interval could be forexample be of the order of minutes, e.g. a 5 minute interval, a 10minute interval, etc. The calculated likelihood for the time intervalmay then be ascribed to a particular time within that time interval.That time value may conveniently be the beginning of the time interval.

The estimated likelihood a dedicated bearer will be established for theUE 802 within a specific time interval may be calculated as a functionof: i) the number of times an dedicated bearer was established for theUE 802 within the specific time interval for each day the sessioninformation was collected and recorded; and ii) the number of days overwhich the session information was collected and recorded. As a simpleexample, if the session information was recorded over a time period of10 days, and a dedicated bearer was established for the UE 802 withinthe time interval between 10:00 am and 10:10 am on 7 of those days, theestimated likelihood a dedicated bearer will be established for the UE802 within the time interval between 10:00 am and 10:10 am may becalculated as 0.7, or 70%. The estimated likelihood for the timeinterval may then be ascribed to the time value defining the beginningof the time interval (in this example, 10:00 am).

It will be appreciated that other, more complex, predictive calculationsmay be used.

In some examples, the network cell location is not taken into account inthe predictive calculations performed by the computation unit 824. Thatis, the estimated likelihood of dedicated bearer establishment may becalculated using only the timing information in the data store 822, andexcluding the location information. This may be useful for estimatingwhen dedicated bearers are likely to be established for UE's that useregularly use the same services at similar times for each day, but fromdifferent locations.

In other examples, the estimated likelihood a dedicated bearer will beestablished may be calculated by the computation unit 824 additionallyin dependence on the location of the UE 802 within the network. That is,the calculation unit 824 may use the location information recorded inthe data store 822 to estimate: i) the likelihood dedicated bearer willbe established for the UE 802 at one or more time values; and ii) thenetwork cell that the dedicated bearer will be established in for the UE802 (i.e. the network cell the device will be located in when thatdedicated bearer is established).

The estimated likelihood a dedicated bearer will be established mayadditionally be calculated by the computation unit 824 in dependence onthe type of application, or service, running on the UE 802. That is, thecomputation unit 824 may use the information recorded in the data store822 to estimate: i) the likelihood a dedicated bearer will beestablished for the UE 802 at one or more time values; and ii) the typeof application, or service, running on the UE 802 that dedicated bearerwill be established for.

In some examples, the computation may estimate: i) the likelihood adedicated bearer will be established for the UE 802 at one or more timevalues; and ii) the network cell that dedicated bearer will beestablished in for the UE 802; and iii) the type of application, orservice, running on the UE 802 that dedicated bearer will be establishedfor.

If the estimated likelihood a dedicated bearer will be established forthe UE 802 at a particular time value exceeds a specified threshold, thecomputation unit 824 may predict that the dedicated bearer will beestablished for the UE 802 at that time value (at 906). The computationunit 824 may additionally predict which network cell the dedicatedbearer will be established in, and/or the application or service runningon the UE 802 the dedicated bearer will be established for.

Decision logic may be used to implement 906. That is, the computationunit 824 may make a prediction that the dedicated bearer will beestablished at a time value if the associated likelihood exceeds thespecified threshold, and not make a prediction if the likelihood isbelow the specified threshold.

The specified threshold may be set by the PCRF 816. The value of thethreshold may depend on the associated time value. For example, a lowerthreshold may be associated with ‘peak’ time values (e.g. time values atwhich the network is expected to be particularly busy). During thesetime values it may be more important from a performance perspective tohave the dedicated bearer established in time for its use by the UE 802.It may therefore be desirable to lower the threshold to reduce the riskof a bearer not being established for the UE 802 when one was needed.The values of the threshold may alternatively or in addition depend onthe associated type of service the dedicated bearer will be establishedfor. For example, certain types of service (e.g. gaming) are moretime-critical than others (e.g. web browsing). It may therefore bepreferable to have a lower prediction threshold for the moretime-critical services to reduce the risk of a bearer for that servicenot being established for the UE 802 when one was needed.

Thus, in summary, at 904 the computation unit 824 estimates thelikelihood a dedicated bearer will be established for the UE 802 at oneor more time values (and optionally, also the network cell the dedicatedbearer will be established in and/or the service running on the UE 802the dedicated bearer will be established for). If any of those estimatedlikelihoods exceed a specified threshold, then at 906 the computationunit 824 may predict that a dedicated bearer will be established at thecorresponding time value(s) (and optionally, predict the network cellthe dedicated bearer will be established in and/or the service runningon the UE 802 the dedicated bearer will be established for).

At 908, the PCRF 816 initiates the establishment a dedicated bearer forthe UE 802 so that the dedicated bearer is established by the time valueat which the likelihood exceeds the specified threshold (i.e. by thepredicted time value). That is, the PCRF 816 initiates the establishmentof the dedicated bearer at some time prior to the predicted time valueso that the dedicated bearer is established by the predicted time value.The PCRF 816 may initiate the establishment some specified time periodbefore the predicted time value. This time period may be dependent onthe average or typical time taken to establish a dedicated bearer.

If at 904 the computation unit 824 additionally estimates the networkcell the dedicated bearer will be established in for the UE 802, then at406 the PCRF 816 initiates the establishment of the dedicated in thatnetwork cell. That is, the PCRF 816 initiates the establishment of thededicated bearer so it is established the predicted time value and inthe predicted network cell. The establishment of the dedicated bearer isillustrated in FIG. 11.

FIG. 11 shows a call flow for dedicated bearer activation. The call flowis based on the flow for dedicated bearer activation in 3GPP TS 23.401,but with some modifications explained below.

At block 1102, the PCRF 816 initiates establishment of a dedicatedbearer at a predicted time value Tp. This step is not included withinthe conventional call flow for dedicated bearer establishment. Toinitiate establishment of the dedicated bearer, the PCRF 816 sends asession modification message 1104 to the PGW 818. Message 1104 may bereferred to as an IP-CAN Session Modification message, or a QoS policymessage. This message may be sent by the communications module 830 viathe communications interface 820.

The establishment of the dedicated bearer then follows the remainder ofthe call flow. A create bearer request message 1106 is communicated fromthe PGW 818 to the SGW 814, and in response from the SGW 814 to the MME810 (message 1108). The MME 810 then operates to establish the radiobearer between the UE 802 and eNodeB 804 through the exchange ofmessages denoted generally at 1110 (steps 4 to 7). The MME 810 thencommunicates a create bearer response message 1112 from the MME 810 tothe SGW 814, and the SGW 814 communicates the create bearer responsemessage 1114 to the PGW 818. In response, the PGW 818 communicates thesession modification complete message 1116 to the PCRF 816 to completeestablishment of the dedicated bearer. The message 1116 may also bereferred to as an IP-CAN Session Modification.

The PCRF 816 may be configured to initiate deactivation of the dedicatedbearer established at step 908 in response to determining that thededicated bearer is not used by the UE 802 within a specified timeperiod tmax of its establishment by the PCRF 816. This can convenientlyfree up resources of the network if it is determined they are not beingused by the UE 802.

The time period tmax may be of the order of minutes. In some examples,tmax=1, 2, 3, 4, 5 or 10 minutes.

To monitor whether to deactivate the established dedicated bearer, thePCRF 816 may start timer 826 when the dedicated bearer is established(e.g. at time Tp). If the PCRF 816 detects that the dedicated bearer hasnot been used by the UE 802 upon expiry of the waiting time tmax, itinitiates deactivation of the dedicated bearer. The timer may then bereset.

FIG. 12 is a call flow illustrating the deactivation of the dedicatedbearer established from predictions made at 904 from the session datacollected at 902.

FIG. 12 is based on the call flow illustrating dedicated bearerdeactivation per 3GPP TS 23.401, but with some modifications which willbe explained below.

1 a (denoted at 1202) is a new task performed by the PCRF 816 inaccordance with the present disclosure. In accordance with this example,the PCRF 816 determines that the established dedicated bearer has notbeen used by the UE 802 within the time period tmax of its predictedtime. Thus, the UE 802 may be in an idle state. In response to thisdetermination, the PCRF 816 sends a session modification request message1204 to the PGW 818. The session modification request message indicatesthe dedicated bearer is to be deactivated. This message may be sent bythe communications module 830 through the interface 820.

Message 1204 causes the PGW 818 to send a delete bearer request message1206 to the SGW 814, which in turn communicates the delete bearerrequest message 1208 to the MME 810. The call flow then continuesthrough the exchange of messages denoted generally at 1210 (4 to 11) inaccordance with 3GPP TS 23.401.

The above-described examples illustrate techniques for predicting a timewhen a bearer (e.g. a radio, E-RAB or dedicated EPS bearer) will be usedby a UE within a communication network, and initiating the establishmentof the bearer so that it can be established at the predicted time (andoptionally network cell location). These approaches can enhance thebehavior of the network by reducing the delay experienced by the UEwaiting for a required bearer to be established. The approachesdescribed herein enable a bearer to be established for when it is neededby the UE using prediction information calculated from recorded sessiondata. The above examples have been described in the context of LTEnetworks for the purposes of illustration, but it will be appreciatedthat the techniques herein could equally be applied to other networksimplementing bearers.

The applicant hereby discloses in isolation each individual featuredescribed herein and any combination of two or more such features, tothe extent that such features or combinations are capable of beingcarried out based on the present specification as a whole in the lightof the common general knowledge of a person skilled in the art,irrespective of whether such features or combinations of features solveany problems disclosed herein, and without limitation to the scope ofthe claims. The applicant indicates that aspects of the presentdisclosure may consist of any such individual feature or combination offeatures. In view of the foregoing description it will be evident to aperson skilled in the art that various modifications may be made withinthe scope of the disclosure.

1. A method of establishing bearers for a device in a wirelesscommunication network, comprising: collecting data for the device over aperiod of time from communication sessions the device participates in,the communication sessions supported by a first bearer and a secondbearer for the wireless communication network wherein the first bearertransports packets of the second bearer between nodes of the wirelesscommunication network; calculating from the collected data a likelihoodthe first bearer will be established for the device at one or moredifferent time values, and predicting the first bearer will beestablished for the device at a time value if the likelihood ofestablishment at that time value exceeds a specified threshold; andinitiating establishment of the first bearer to establish the firstbearer for the predicted time value.
 2. A method as claimed in claim 1,wherein the method further comprises receiving at a node of the wirelesscommunication network an attach request from the device that includes anidentification flag indicating data from communication sessions thedevice participates in is to be collected for the device, wherein datafor the device is collected following receipt of the identificationflag.
 3. A method as claimed in claim 2, wherein the node is a mobilitymanagement entity (MME).
 4. A method as claimed in claim 1, wherein thedata is collected from communication sessions the device participates inover the period of time.
 5. A method as claimed in claim 1, wherein thecollected data comprises timing data indicating time values the firstbearer is established for the device.
 6. A method as claimed in claim 5,wherein the collected data further comprises location data indicating anetwork cell of the wireless communication network the first bearer isestablished in for the device.
 7. A method as claimed in claim 6,wherein the calculating comprises calculating: a likelihood the firstbearer will be established for the device at one or more different timevalues, and the network cell the first bearer will be established in forthe device.
 8. A method as claimed in claim 7, wherein the initiatingcomprises initiating establishment of the first bearer: to establish thefirst bearer for the predicted time; and within the network cell thefirst bearer is predicted to be established in at the predicted timevalue.
 9. A method as claimed in claim 1, wherein the method furthercomprises deactivating the first bearer if it is determined the devicehas not used the first bearer within a specified time period of theestablishment of the first bearer.
 10. A method as claimed in claim 9,further comprising: starting a timer when the first bearer isestablished; and initiating deactivation of the first bearer if thetimer indicates the device has not used the first bearer within thespecified time period.
 11. A method as claimed in claim 1, wherein thefirst bearer is a radio bearer.
 12. A method as claimed in claim 1,wherein the first bearer is an E-UTRAN Radio Access Bearer (E-RAB). 13.A method as claimed in claim 1, wherein the second bearer is a defaultbearer or a dedicated bearer.
 14. A method as claimed in claim 1,wherein the second bearer is an EPS bearer.
 15. An apparatus forestablishing bearers for a device within a wireless communicationnetwork, comprising: a data store configured to collect data for thedevice over a period of time from communication sessions the deviceparticipates in, the communication sessions supported by a first bearerand a second bearer for the wireless communication network wherein thefirst bearer transports packets of the second bearer between nodes ofthe wireless communication network; a computation module configured tocalculate from the collected data a likelihood the first bearer will beestablished for the device at one or more different time values, andpredict the first bearer will be established for the device at a timevalue if the likelihood of establishment at that time value exceeds aspecified threshold; and a communications module configured to initiateestablishment of the first bearer to establish the first bearer for thepredicted time value.